Abstract 717: Detection of premalignancy of esophageal mucosa by multispectral imaging of autofluorescence from protoporphyrin IX

Background: We have recently found that chemically induced esophageal carcinoma emitted a strong fluorescence originating from protoporphyrin IX (PpIX). The aim of this study was to detect early changes in the esophageal mucosa for clarifying the mechanism of carcinogenesis. For this purpose, we established a novel method for detection of premalignancy based on multispectral fluorescence imaging (MFI) of autofluorescence (AF) from tissue. Methods: We made an N-nitroso-methylbutylamine (NMBA)-induced rat esophageal tumor model (15 mg/L in daily drinking water) and extracted the esophagus. The mucosal side was illuminated by an excitation blue light (405 nm) and the emitted light was captured on an EM-CCD detector (512 x 512 pixels), of which each pixel collected a spectrum ranging from 450 nm to 800 nm. The extracted tissues were further analyzed to measure porphyrins by high-performance lipid chromatography (HPLC). Results: When the mucosa was illuminated by the excitation light, AF with a peak at 630 nm was observed in preneoplastic lesions and HPLC revealed that the origin of AF was PpIX. MFI based on the spectral difference clearly visualized preneoplastic lesions: the spectral pattern of the AF from preneoplastic lesions was different from that from normal mucosa, and the spectral difference became greater with increase in the duration of NMBA administration and the concentration of PpIX also increased with the time course. Conclusion: The results showed that MFI of tissue AF has a potential for cancer screening. Citation Format: Toshikatsu Horiuchi, Yuji Morimoto, Hiroaki Taniguchi, Araya Umetsu, Shun-ichiro Ogura, Keiichi Iwaya, Nariyoshi Shinomiya. Detection of premalignancy of esophageal mucosa by multispectral imaging of autofluorescence from protoporphyrin IX. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 717. doi:10.1158/1538-7445.AM2013-717